Biomedical Engineering Reference
In-Depth Information
FIGURE 5.2
Scanning electron micrographs and energy dispersive analysis for X-ray of (A) nanostructured
titanium surface obtained by anodization and (B) nanosized thin CaP coating on titanium produced
by electrochemical deposition. Note the regular array of TiO
2
nanopores of approximately 100 nm in
diameter and the nanosized CaP crystals on titanium surfaces.
studies have demonstrated that these CaP coatings provided titanium implants with an osteoconduc-
tive surface
[5,6]
. Following implantation, the dissolution of CaP coatings in the peri-implant region
increased ionic strength and saturation of blood leading to the precipitation of biological apatite nano-
crystals onto the surface of implants. This biological apatite layer incorporates proteins and promotes
the adhesion of osteoprogenitor cells that would produce the extracellular matrix of bone tissue.
Furthermore, it has also been shown that osteoclasts, the bone resorbing cells, are able to degrade the
CaP coatings through enzymatic ways and create resorption pits on the coated surface
[6]
. Finally, the
presence of CaP coatings on metals promotes an early osseointegration of implants with a direct bone
bonding as compared to non-coated surfaces. The challenge is to produce CaP coatings that would dis-
solve at a similar rate than bone apposition in order to get a direct bone contact on implant surfaces.
This chapter reviews the different steps of the interactions between biological fluids, cells, tissues,
and surfaces of implants. Recent nanoscale surface modifications and CaP coating technologies of
dental implants are discussed. The sequence of biological events in relation to surface properties is
related. Mechanisms of interaction with blood, platelets, hematopoietic, and mesenchymal stem cells
(MSCs) on the surface of implants are described. These early events have shown to condition the
